Optimal design of a cathode flow field with a new arrangement of baffle plates for a high clean power generation of a polymer electrolyte membrane fuel cell

Abstract

Polymer electrolyte membrane fuel cell is a clean and promising energy device in the near future; the present work proposes newly designed baffle plates that feature unequal height and space distance arrangements in the cathode flow field of fuel cells. Using a three dimensions multiphase fuel cell model, the effects of various newly designed baffle plates with different numbers, unequal height and space distance arrangements on the oxygen diffusion, water transport behavior and performance of a fuel cell are comprehensively evaluated. The results show that the baffle plates significantly promote oxygen diffusion and water elimination in fuel cells compared to the regular straight flow field, especially in the regions around the baffle plates due to the convection effect. A gradually increasing height and a decreasing space distance between the baffle plates can further relieve water flooding and oxygen starvation in the porous electrodes downstream of the channel under high current densities; hence, they significantly improve the maximum power density by 9.67% compared to the regular flow field without baffle plates. In addition, the optimal newly designed baffle plate flow field pattern exhibits uniform physical quantities with a relatively low-pressure loss along the flow channel, which reduces the pumping power to supply reactants and favors the energy efficiency of fuel cells.